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Background/Introduction: Thromboinflammation in severe COVID-19 is associated with disease severity and outcome. The kallikrein pathway is suggested to mediate thromboinflammation in COVID-19 by activating inflammatory pathways and contactmediated coagulation. Purpose(s): The DAWn-antico study investigates if a multitarget modulation of the thromboinflammatory response improves outcomes in hospitalized patients with severe COVID-19. Method(s): In this multicenter open-label randomized clinical trial (EudraCT 2020-001739-28), patients hospitalized with COVID- 19 were 1:2 randomized to receive standard of care (SOC) or SOC plus study intervention. The intervention consisted of aprotinin (2,000,000 IE IV four times daily) combined with low-molecular-weight heparin (LMWH;SC 50 IU/kg twice daily at the ward, 75 IU/kg twice daily at intensive care). Additionally, patients with predefined hyperinflammation received the interleukin-1- receptor antagonist anakinra (100mg IV four times daily). The primary outcome was time to a sustained 2-point improvement on the 7-point WHO ordinal scale for clinical status, or discharge. The trial was funded by Life Sciences Research Partners, Research Foundation Flanders (G0G4720N), and KU Leuven COVID-19 fund. Result(s): Between 24 June 2020 and 01 February 2021, 105 patients were randomized, and 102 patients were included in the full analysis set (intervention N=67 vs. SOC N=35). Twenty-five patients from the intervention group (37%) received anakinra. The intervention did not affect the primary outcome (HR 0.77 [CI 0.50;1.19], p=0.24) or mortality (intervention n=3 (4.6%) vs. SOC n=2 (5.7%), HR 0.82, [CI 0.14;4.94], p=0.83). There was one treatment-related adverse event in the intervention group (hematuria, 1.49%). There was one thrombotic event in the intervention group (1.49%) and one in the SOC group (2.86%), but no major bleedings. Conclusion(s): In hospitalized COVID-19 patients, modulation of thromboinflammation with high-dose aprotinin and LMWH with or without anakinra did not improve outcome in patients with moderate to severe COVID-19. (Disclosure: this RCT was presented at ISTH 2022 in London and will be published in Research and Practise in Thrombosis and Haemostasis).
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Background. COVID-19-associated pulmonary aspergillosis (CAPA) is a severe superinfection with the fungus Aspergillus frequently affecting critically ill COVID-19 patients. Pathophysiological insight, key to improve diagnostic and immunomodulatory therapeutic options, is lacking. Methods. We performed single-cell RNA sequencing (scRNA-seq) on 37 bronchoalveolar lavage (BAL) samples from 37 critically ill COVID-19 patients. Three groups were defined: patients who did not develop aspergillosis (COVID-19-only, n=22), CAPA patients with sampling < 5 days after CAPA diagnosis (early CAPA, n=6) and CAPA patients with sampling 5-11 days after CAPA diagnosis (late CAPA, n=9). All CAPA patients had probable/proven CAPA according to the 2020 ECMM/ISHAM consensus criteria. Additionally, we assessed neutrophil extracellular trap (NET) levels in a separate cohort of 33 biobanked COVID-19-only BAL samples and 24 early CAPA samples. Results. A total of 69008 cells passed quality filtering. CAPA patients had significantly lower BAL neutrophil proportions than COVID-19-only patients, particularly in early CAPA (Fig. 1A). Pseudotime inference revealed two neutrophil trajectories: a regular maturation trajectory, and a trajectory giving rise to "hybrid" neutrophils which express genes encoding proteins with antigen-presenting functions (Fig. 1B). The latter trajectory was dominant in CAPA patients (Fig. 1C). NETosis analyses revealed significantly higher levels of citrullinated histone H3 DNA complexes (H3Cit-DNA) in CAPA patients (Fig. 2A). This explains the low CAPA BAL neutrophil proportions, as neutrophils that underwent NETosis are no longer detected via scRNA-seq. CAPA patients with the lowest H3Cit-DNA levels had significantly decreased survival rates (Fig. 2B). Panel (A): BALF neutrophil proportions as analyzed by single-cell RNA sequencing using the Seurat R package are significantly lower in CAPA patients compared to COVID-19-only patients. Patients with early CAPA have significantly lower BALF neutrophil proportions than patients with late CAPA. Macrophage/monocyte and epithelial cell proportions are reciprocally increased in CAPA patients compared to COVID-19-only patients. P-values shown for differences between the pooled CAPA patients and the COVID-19-only patients. P-values were calculated using a generalized linear model correcting for age, Charlson Comorbidity Index at hospital admission, and administration of corticosteroids (prednisone equivalent dose 20 mg or higher) within 48 hours of BALF sampling. Panel (B): Two trajectories are defined using pseudotime inference calculated using the Slingshot R package: a trajectory dominant in COVID-19-only patients with regular maturation of progenitor neutrophils, and a trajectory dominant in CAPA patients with maturation towards a 'hybrid neutrophil' state, with neutrophils expression genes encoding proteins with functions in antigen presentation. Subsequently, the hybrid neutrophil proportion is significantly higher in CAPA patients compared to COVID-19-only patients, and is significantly higher in patients with early CAPA than those with late CAPA. The mature neutrophil proportion is reciprocally reduced in CAPA patients. P-values shown for differences between the pooled CAPA patients and the COVID-19-only patients. P-values were calculated using a generalized linear model correcting for age, Charlson Comorbidity Index at hospital admission, and administration of corticosteroids (prednisone equivalent dose 20 mg or higher) within 48 hours of BALF sampling. Panel (A): Myeloperoxidase (MPO) DNA levels were analyzed as measure for general NET-formation, while citrullinated histone H3 bound DNA (H3Cit-DNA) levels were analyzed as more specific PAD4-dependent NET-formation, in BALF samples from early CAPA and COVID-19-only patients. A trend towards higher MPO-DNA levels was found in early CAPA patients, while H3Cit-DNA levels were significantly higher in early CAPA compared to COVID-19-only patients. P-values calculated using Mann-Whitney U test. Panel (B): Kaplan-Meier analy is of patients with NETosis analyses, divided in early CAPA and COVID-19-only patients and subdivided according to H3Cit-DNA levels (cut-off at 20000 ng/mL for early CAPA and at 8000 ng/mL for COVID-19-only). Log-rank test was used to compare survival distributions. For the comparison early CAPA (low H3Cit-DNA) versus early CAPA (high H3Cit-DNA), the log-rank p-value was 0.033. Conclusion. CAPA patients display extremely high levels of released NETs in the lower respiratory tract, associated with a shift from the normal neutrophil maturation process towards "hybrid neutrophil" formation, probably upon encountering the fungus. In contrast to high NETosis contributing to mortality in severe COVID-19, CAPA patients likely require these NETs to survive aspergillosis. BAL NET levels hold promise as a tool to guide diagnosis, prognosis and treatment in these patients.
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Background: COVID-19 represents a perfect storm for release of neutrophil extracellular traps (NETs) and resultant pathology from immunothrombosis. Levels of NETs in circulation are regulated by endogenous plasma DNases, which have been shown to be reduced in various diseases including myocardial infarction and sepsis. We previously reported elevated NET biomarkers in admission samples from our first wave study cohort. Aim(s): To characterize DNase activity and biomarkers of released NETs in the context of COVID-19 immunothrombosis. Method(s): With ethical permission and informed consent, we prospectively collected citrated platelet-poor plasma samples from patients admitted to the COVID ward (55 patients) or intensive care unit (216 patients) from March 2020-December 2021 as part of the COntAGIouS trial at UZ Leuven in Belgium (NCT04327750), with special attention paid to sample preparation and storage to preserve NET fragments and DNase activity. Consecutive samples were obtained within 48 hours of admission, between days 6-8, and upon hospital or ICU discharge. Analysis was batch-performed for MPO, MPO-DNA, PF4, sP-selectin, citrullinated histones, DNase activity, VWF:Ag, and FVIII:Ag levels. Result(s): In ICU patients, MPO, VWF, sP-selectin, and NET biomarkers were elevated throughout hospitalization, peaking at day 6-8 after admission, whereas PF4 and FVIII remained highly elevated through the time of ICU discharge. DNase activity was decreased in admission samples, normalized at day 6-8, and strongly increased at the time of discharge, indicating a potential compensatory mechanism. DNase activity was negatively correlated with MPO-DNA values (r = -0.29, p = 0.0013). sPselectin and NET levels were significantly higher in admission samples for patients who experienced a thrombotic event in the period during hospitalization, including pulmonary embolism, DVT, myocardial infarction, and/or stroke. Conclusion(s): Elevated NET levels and decreased DNase activity in plasma are correlated in severe COVID-19, together with elevated markers of thrombotic risk. Approaches to restore DNase activity in plasma may be beneficial in COVID-19-associated immunothrombosis.
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Background: Thromboinflammation in severe COVID-19 is associated with disease severity and inferior outcome. Evidence suggests that the kallikrein pathway potentially plays a vital role in COVID-19 associated thromboinflammation as it both activates downstream inflammatory pathways and contact-mediated coagulation. Aim(s): To investigate whether modulation of this pronounced thromboinflammatory response can improve outcomes in hospitalized patients with severe COVID-19. Method(s): This multicenter randomized clinical trial was approved by the ethics committee and supported by the KU Leuven COVID-19 fund and Research Foundation Flanders (FWO). After informed consent, eligible patients were 1:2 randomized to receive standard of care (SOC) or SOC plus study intervention (figure 1). The intervention consisted of off-label -kallikrein-inhibiting -aprotinin combined with low molecular weight heparin (LMWH). Additionally, patients with predefined hyperinflammation were treated with the interleukin-1 receptor antagonist anakinra. The primary endpoint was time to sustain a 2-point improvement in the WHO ordinal scale for clinical status. Result(s): Three hospitals in Belgium included 102 patients (35 SOC vs. 67 intervention). Twenty-five patients from the intervention group (37%) were treated with anakinra. Patients had elevated D-dimers (mean 1012.4 mug/L;SD 991.9 mug/L) and C-reactive protein (mean 81.4 mg/L;SD 59.6 mg/L) at admission confirming baseline activation of coagulation and inflammatory pathways. During hospitalization, 37% of patients were admitted to the ICU (29% SOC vs. 42% intervention), and 20% needed invasive ventilation (12% SOC vs. 25% intervention). The intervention did not affect the time to sustained clinical improvement or hospital discharge (figure 2), nor secondary clinical endpoints. Except for D-dimers at day 3, there was no significant C-reactive protein or D-dimer reductions. There were no differences in treatment-related adverse events. Conclusion(s): In hospitalized COVID-19 patients, additional modulation of thromboinflammation with high-dose aprotinin and LMWH with or without anakinra was feasible and safe but did not improve clinical nor biochemical outcomes.
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Background : Markers of both inflammation and coagulation are linked to clinical outcome in coronavirus disease 2019 (COVID-19). Binding of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to the angiotensin-converting enzyme 2 receptor, which is involved in kinin breakdown, interferes with the kallikreinkinin pathway. This could result in increased vascular permeability, fluid excess in the lungs and pulmonary edema. Furthermore, the kallikrein-kinin pathway links coagulation and inflammation through its interactions with the contact activation pathway of coagulation via factor XII and with neutrophil extracellular traps (NETs). These insights could help to explain the clinical presentation of COVID-19 pneumonia with pulmonary coagulopathy and the high incidence of thromboembolic complications in COVID-19. Aims : Given the lack of clinical evidence to support this hypothesis, we studied the kallikrein-kinin system in bronchoalveolar lavage (BAL) fluid. Methods : In BAL fluid samples from patients with or without COVID-19, we performed in-depth analyses of kinin peptides (bradykinin, Lys-bradykinin, Lys-bradykinin-(1-8), bradykinin-(1-8), bradykinin-(1-7), and bradykinin-(1-5)) using a liquid chromatography with tandem mass spectrometry assay, along with measurements of plasma and tissue kallikrein hydrolytic activity and myeloperoxidase (MPO)-DNA complexes as a biomarker for NETs. Informed consent and ethical approval were obtained. Results : We observed higher levels of the most downstream kinin peptide bradykinin-(1-5) (Figure 1), higher tissue kallikrein activity (Figure 2), and higher levels of MPO-DNA complexes (699.0 ng/mL [66.0-142621.0], median [range], n = 21 vs 70.5 [9.9-960.0], n = 19;P < 0.001) in BAL fluid from patients with COVID-19 compared to those in BAL fluid from patients without COVID-19. Conclusions : Our data support the hypothesis that SARS-CoV-2 induces dysregulation of the kallikrein-kinin system, which contributes to thromboinflammation in COVID-19. These findings encourage the investigation of drugs that target the kallikrein-kinin system as a potential treatment option for patients with COVID-19.
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Invasive pulmonary aspergillosis is emerging as a secondary infection in patients with COVID-19, which can present as alveolar disease, airway disease (ie, invasive Aspergillus tracheobronchitis), or both. Histopathology of invasive Aspergillus tracheobronchitis in patients with severe COVID-19 confirms tracheal ulcers with tissue invasion of Aspergillus hyphae but without angioinvasion, which differs from patients with severe influenza, where early angioinvasion is observed. We argue that aggregation of predisposing factors (eg, factors that are defined by the European Organisation for Research and Treatment of Cancer and Mycoses Study Group Education and Research Consortium or genetic polymorphisms), viral factors (eg, tropism and lytic effects), immune defence factors, and effects of concomitant therapies will determine whether and when the angioinvasion threshold is reached. Management of invasive Aspergillus tracheobronchitis should include reducing viral lytic effects, rebalancing immune dysregulation, and systemic and local antifungal therapy . Future study designs should involve approaches that aim to develop improved diagnostics for tissue invasion and airways involvement and identify the immune status of the patient to guide personalised immunotherapy.
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Background: SARS-CoV-2 pandemic has deeply modified healthcare seeking and services in Europe since February 2020 with delays in treatment delivery and changes in the standards of care. The organization of cancer centers (CC) has been transformed to minimize virus exposure in cancer patients (pts). Real-time assessment of the impact on cancer outcomes can optimize decision-making for future epidemic episodes. Methods: A discrete-event simulation (DES) model was developed to model individual pt pathways during the pandemic in a context of constrained medical resources. Cancer pt care is modeled based on pandemic-adapted guidelines for medical practice. Pt flow is derived from medico-administrative databases using time series methods to estimate the proportion of punctual / late visits and associated delay and to extrapolate future flows. Finally, the impact of modified care on survival is estimated using literature data. Results: From March to December 2020, based on data from Gustave Roussy CC in France (n= 4877 included pts), estimated overall treatment delay is <= 7 days in 86,6% of pts and 5,2% of pts have a delay higher than 2 months. More than 94% of this duration is delay in pt request for care, causing 99 pts to suffer a major prognosis change upon arrival. Delayed pt flows result in a highly time-variable use of medical resources, with important queues forecast for surgery care and chemotherapy. The handling of such queues will require intensified healthcare professionals effort. Projections show that, in the best-case scenario, ie without a 2nd pandemic wave, treatment delays and modifications will result in around 49 additional 5-year cancer-specific deaths (+ 2,25% of 5-year deaths), mainly in liver, sarcomas and head and neck cancer pts. Conclusions: In a resource-constrained context, optimization of the benefit-risk ratio between COVID-19 and cancer care is key. Simulations of individual projections from actual hospital data, show a 2.25% increase of the 5-year risk of death and that pandemic-related cancer burden is mainly due to patient-induced lateness in seeking care. Defining optimal strategies in terms of screening, monitoring and prioritization for care could minimize the impact of future pandemic episodes. Legal entity responsible for the study: The authors. Funding: Has not received any funding. Disclosure: A. Bardet: Advisory/Consultancy: Roche. M. Faron: Travel/Accommodation/Expenses: Ipsen;Travel/Accommodation/Expenses: Novartis;Travel/Accommodation/Expenses: Pfizer;Honoraria (self): HRA Pharma;Honoraria (self): Ipsen. I. Borget: Honoraria (self): Merck;Honoraria (self): CSL Berhing;Honoraria (self): Allergan;Honoraria (self): Novartis;Research grant/Funding (institution): BMS. S. Michiels: Advisory/Consultancy: IDDI;Advisory/Consultancy: Janssen Cilag;Honoraria (self), IDMC member: Hexal;Honoraria (self), IDMC member: Steba;Honoraria (self), IDMC member: IQVIA;Honoraria (self), IDMC member: Roche;Honoraria (self), IDMC member: Sensorion;Honoraria (self), IDMC member: Biophytis;Honoraria (self), IDMC member: Servier;Honoraria (self), IDMC member: Yuhan. F. Barlesi: Honoraria (self), further elements to be provided: AstraZeneca;Honoraria (self): Bayer;Honoraria (self): Bristol-Myers Squibb;Honoraria (self): Boehringer-Ingelheim;Honoraria (self): Eli Lilly Oncology;Honoraria (self): F.Hoffmann-La Roche Ltd;Honoraria (self): Novartis;Honoraria (self): Merck;Honoraria (self): MSD;Honoraria (self): Pierre Fabre;Honoraria (self): Pfizer;Honoraria (self): Takeda;Honoraria (institution): AbbVie;Honoraria (institution): Amgen;Honoraria (institution): AstraZeneca;Honoraria (institution): Bayer;Honoraria (institution): Bristol-Myers Squibb;Honoraria (institution): Boehringer-Ingelheim;Honoraria (institution): Eisai;Honoraria (institution): Eli Lilly Oncology;Honoraria (institution): F. Hoffmann-La Roche Ltd;Honoraria (institution): Genentech;Honoraria (institution): Ipsen;Honoraria (institution): Ignyta;Honoraria (institution): Innate Pharma;Honoraria (institu ion): Loxo;Honoraria (institution): Novartis;Honoraria (institution): MedImmune;Honoraria (institution): Merck, MSD, Pierre Fabre, Pfizer, Sanofi-Aventis, Takeda;Research grant/Funding (institution): AstraZeneca, BMS, Merck, Pierre Fabre, F. Hoffmann-La Roche Ltd. J. Bonastre: Honoraria (self): Bristol-Myers Squibb;Advisory/Consultancy: Bristol-Myers Squibb;Advisory/Consultancy: MSD;Advisory/Consultancy: PharmaMar (Inst);Advisory/Consultancy: Bristol-Myers Squibb (Inst);Advisory/Consultancy: Merck Serono;Travel/Accommodation/Expenses: Bristol-Myers Squibb. All other authors have declared no conflicts of interest.
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OBJECTIVE: SARS CoV-2 is an epidemic viral infection that can cause mild to severe lung involvement. Newly apprehended knowledge on thoracic imaging abnormalities and the growing clinical experience on the evolution of this disease make the radiographic follow-up of hospitalized patients relevant. The value of consecutive bedside lung ultrasonography in the follow-up of hospitalized patients with SARS CoV-2 pneumonia and its correlation with other clinical and laboratory markers needs to be evaluated. METHODS: We assessed 39 patients [age: 64 y(60.1-68.7)] with confirmed SARS CoV-2 pneumonia. A total of 24 patients were hospitalized until the follow-up test, 9 were discharged early and 6 required a transfer to critical care unit. Two ultrasound scans of the lung were performed on day 1 and 4 of patients' hospitalization. Primary endpoint was the magnitude of association between a global lung ultrasound score (LUS) and clinical and laboratory markers. Secondary endpoint was the association between the evolution of LUS with the corresponded changes in clinical and laboratory outcomes during hospitalization period. RESULTS: LUS score on admission was higher among the deteriorating patients and significantly (P=0.038-0.0001) correlated (Spearman's rho) with the levels of C-reactive protein (0.58), lymphocytes (-0.33), SpO2 (-0.48) and oxygen supplementation (0.48) upon admission. The increase in LUS score between the two scans was significantly correlated (0.544, P=0.006) with longer hospital stay. CONCLUSION: Lung ultrasound assessment can be a useful as an imaging modality for SARS CoV-2 patients. Larger studies are needed to further investigate the predictive role of LUS in the duration and the outcome of the hospitalization of these patients.
Subject(s)
COVID-19 , Pneumonia , Hospitalization , Humans , Lung/diagnostic imaging , Middle Aged , Pilot Projects , Prognosis , SARS-CoV-2 , UltrasonographyABSTRACT
The COVID-19 pandemic poses a major burden on healthcare and economic systems across the globe. Even though a majority of the population develops only minor symptoms upon SARS-CoV-2 infection, a significant number are hospitalized at intensive care units (ICU) requiring critical care. While insights into the early stages of the disease are rapidly expanding, the dynamic immunological processes occurring in critically ill patients throughout their recovery at ICU are far less understood. Here, we have analysed whole blood samples serially collected from 40 surviving COVID-19 patients throughout their recovery in ICU using high-dimensional cytometry by time-of-flight (CyTOF) and cytokine multiplexing. Based on the neutrophil-to-lymphocyte ratio (NLR), we defined four sequential immunotypes during recovery that correlated to various clinical parameters, including the level of respiratory support at concomitant sampling times. We identified classical monocytes as the first immune cell type to recover by restoration of HLA-DR-positivity and the reduction of immunosuppressive CD163 + monocytes, followed by the recovery of CD8 + and CD4 + T cell and non-classical monocyte populations. The identified immunotypes also correlated to aberrant cytokine and acute-phase reactant levels. Finally, integrative analysis of cytokines and immune cell profiles showed a shift from an initially dysregulated immune response to a more coordinated immunogenic interplay, highlighting the importance of longitudinal sampling to understand the pathophysiology underlying recovery from severe COVID-19.
Subject(s)
COVID-19/immunology , Critical Illness , Leukocyte Count , SARS-CoV-2 , Acute-Phase Proteins/analysis , Antigens, CD/analysis , COVID-19/blood , Convalescence , Cytokines/blood , Female , Follow-Up Studies , HLA-DR Antigens/analysis , Humans , Intensive Care Units/statistics & numerical data , Length of Stay/statistics & numerical data , Lymphocyte Count , Lymphocyte Subsets , Male , Middle Aged , Monocytes , Neutrophils , Pandemics , Prognosis , Prospective StudiesABSTRACT
BACKGROUND: The peak of the global COVID-19 pandemic has not yet been reached, and many countries face the prospect of a second wave of infections before effective vaccinations will be available. After an initial phase of viral replication, some patients develop a second illness phase in which the host thrombotic and inflammatory responses seem to drive complications. Severe COVID-19 disease is linked to high mortality, hyperinflammation, and a remarkably high incidence of thrombotic events. We hypothesize a crucial pathophysiological role for the contact pathway of coagulation and the kallikrein-bradykinin pathway. Therefore, drugs that modulate this excessive thromboinflammatory response should be investigated in severe COVID-19. METHODS: In this adaptive, open-label multicenter randomized clinical trial, we compare low molecular weight heparins at 50 IU anti-Xa/kg twice daily-or 75 IU anti-Xa twice daily for intensive care (ICU) patients-in combination with aprotinin to standard thromboprophylaxis in hospitalized COVID-19 patients. In the case of hyperinflammation, the interleukin-1 receptor antagonist anakinra will be added on top of the drugs in the interventional arm. In a pilot phase, the effect of the intervention on thrombotic markers (D-dimer) will be assessed. In the full trial, the primary outcome is defined as the effect of the interventional drugs on clinical status as defined by the WHO ordinal scale for clinical improvement. DISCUSSION: In this trial, we target the thromboinflammatory response at multiple levels. We intensify the dose of low molecular weight heparins to reduce thrombotic complications. Aprotinin is a potent kallikrein pathway inhibitor that reduces fibrinolysis, activation of the contact pathway of coagulation, and local inflammatory response. Additionally, aprotinin has shown in vitro inhibitory effects on SARS-CoV-2 cellular entry. Because the excessive thromboinflammatory response is one of the most adverse prognostic factors in COVID-19, we will add anakinra, a recombinant interleukin-1 receptor antagonist, to the regimen in case of severely increased inflammatory parameters. This way, we hope to modulate the systemic response to SARS-CoV-2 and avoid disease progressions with a potentially fatal outcome. TRIAL REGISTRATION: The EU Clinical Trials Register 2020-001739-28 . Registered on April 10, 2020.
Subject(s)
COVID-19/complications , Inflammation/etiology , SARS-CoV-2/genetics , Venous Thromboembolism/etiology , Antirheumatic Agents/administration & dosage , Antirheumatic Agents/therapeutic use , Aprotinin/administration & dosage , Aprotinin/therapeutic use , Belgium/epidemiology , Bradykinin/drug effects , Bradykinin/metabolism , COVID-19/epidemiology , COVID-19/virology , Critical Care/statistics & numerical data , Drug Therapy, Combination , Female , Heparin, Low-Molecular-Weight/administration & dosage , Heparin, Low-Molecular-Weight/therapeutic use , Humans , Incidence , Inflammation/epidemiology , Inflammation/metabolism , Inflammation/prevention & control , Interleukin 1 Receptor Antagonist Protein/administration & dosage , Interleukin 1 Receptor Antagonist Protein/therapeutic use , Kallikreins/drug effects , Kallikreins/metabolism , Male , Outcome Assessment, Health Care , SARS-CoV-2/drug effects , Severity of Illness Index , Venous Thromboembolism/epidemiology , Venous Thromboembolism/metabolism , Venous Thromboembolism/prevention & controlABSTRACT
The COVID-19 pandemic poses a major burden on health-care and economic systems across the globe. Even though a majority of the population only develops minor symptoms upon SARS-CoV2 infection, a significant proportion are hospitalized at intensive care units (ICU) requiring critical care. While insights into the early stages of the disease are gradually expanding, the dynamic immunological processes occurring in critically ill patients throughout their recovery at ICU are far less understood. Here, we have analysed longitudinally collected, whole blood samples of 40 surviving COVID-19 patients during their recovery at ICU using high-dimensional cytometry by time-of-flight (CyTOF) and cytokine multiplexing. Based on the neutrophil to lymphocyte ratio (NLR), we defined 4 sequential immunotypes during recovery that correlated to various clinical parameters, including the level of respiratory support at concomitant sampling times. We also identified classical monocytes as the first immune cell type to recover by restoring HLA-DR-positivity and by reducing the immunosuppressive CD163+ monocyte population, followed by the recovery of CD8+ and CD4+ T cell, and mDC populations. The identified immunotypes also correlated to aberrant cytokine and acute-phase reactant levels. Finally, integrative analysis of cytokines and immune cell profiles showed a shift from an initially dysregulated immune response to a more coordinated immunogenic interplay, highlighting the importance of longitudinal sampling to understand the pathophysiology underlying recovery from severe COVID-19.
Subject(s)
Critical Illness , Severe Acute Respiratory Syndrome , COVID-19ABSTRACT
Background: Clinical data suggest an aggravated COVID-19 disease course in cancer patients treated with immune checkpoint inhibitors (ICI). European guidelines advise to defer ICI therapy until complete resolution of COVID-19. However, mechanistic insight into how ICI impacts COVID-19 immunopathology is absent. Methods: We performed single-cell RNA- and T-Cell Receptor-sequencing (TCR-seq) on bronchoalveolar lavage fluid of COVID-19 pneumonia (n=19) and non-COVID pneumonia (n=10), and co-analyzed CD8+ T-cells with publicly available tumor-infiltrating T-cell data of treatment-naïve and ICI-treated patients (Sade-Feldman, Cell, 2018;Lambrechts, Nat Med, 2018). Cell lineages were determined by trajectory inference (Slingshot, Monocle v2) and stratified per condition. Pathogen- or tumor-directed T-cells were defined based on clonal selection (Zhang, Nature, 2018). To identify ICI responsive cells, we calculated a score derived from a validated gene set denoting ICI reactivity (Okamura, J. Autoimmun, 2019). Results: We identified 3 CD8+ T-cell lineages, with ‘Naïve’ T-cells transitioning into ‘Effector Memory’ cells and then branching into either ‘Recently Activated Effector Memory (TEMRA)’, ‘Exhausted (TEX)’ or ‘Resident Memory (TRM)’ T-cells. In COVID-19, clonal expansion indicating a SARS-CoV-2 antigen-specific T-cell response, was mainly observed in the highly cytotoxic ‘TEMRA’ lineage. In contrast, tumor-specific T-cells were found in the ‘TEX’ lineage. Of importance, the ICI responsiveness score was significantly higher in the non-pathogen-directed ‘TRM’ and ‘TEX’ cells in COVID-19. In cancer, ‘TEX’ cells were shown to be ICI responsive as expected. [Formula presented] Conclusions: We are the first to provide a mechanistic rationale for an aggravated COVID-19 disease course in ICI-treated patients. Whereas ICI reactivates tumor-directed ‘exhausted’ T-cells in cancer, it preferentially potentiates non-pathogen-directed T-cells in COVID-19, thereby contributing to lung damage without boosting the antiviral immune response. Clinical trial identification: In-depth Immunological Investigation of COVID-19 (COntAGIouS). - Clinical Trial identifier: NCT04327570. - Ethical approval obtained by the Ethics Committee of University Hospitals - KU Leuven. File number S63881. Legal entity responsible for the study: University Hospitals - KU Leuven. Funding: Kom op tegen Kanker (Stand up to Cancer). Disclosure: All authors have declared no conflicts of interest.
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Critically ill COVID-19 patients often develop a severe pro-thrombotic milieu, as reflected by the markedly increased d-dimer levels. Several cohort studies have reported high rates of thrombotic complications, including deep venous thrombosis (DVT) and pulmonary embolism (PE), myocardial infarction, stroke and microvascular thrombosis. Accordingly, COVID-19 patients who are hospitalized either at a normal, non-intensive care unit (ICU) or at the ICU need to receive appropriate dosages of anticoagulant therapy to prevent or treat these thrombotic complications. This manuscript summarizes the institutional guidance for the antithrombotic prophylaxis and treatment of VTE as outlined by a multidisciplinary team of experts during the first weeks of the COVID-19 pandemic in Europe. Controlled studies are needed to verify the optimal anticoagulation for both prophylaxis and treatment.